After years of happily using the ASIAIR Pro, I've finally decided it was time for an upgrade: meet the ASIAIR Plus. In this post I'll walk through what's different between the two devices, the features that convinced me to make the switch, and how I've configured the new one ready for its first clear night.
Let me start by saying the ASIAIR Pro is a fantastic little piece of kit. By astrophotography standards it sits at a relatively low price point, and for the amount it offers and does, it's worth every penny. So this wasn't an upgrade made out of frustration; it's just that after a few years the Plus had accumulated enough improvements to justify the swap. Amusingly, the top three features printed on the side of the box turned out to be precisely the ones I bought it for.
The rest of the rig it'll be running is unchanged:
- ZWO ASI 2600MM Pro (+ Antlia Sii, Ha, Oiii & LRGB-V Pro Filters)
- ZWO ASI 662MC
- William Optics Zenithstar 81 + Sky-Watcher HEQ5 Pro
- William Optics 50mm Slide-base Uniguide Scope + ZWO ASI 120mm Mini
- ZWO ASIAir Pro
What's different?
Unboxing the Plus, you get a little quick start guide (which I probably won't read), the device itself looking very shiny and new, a Wi-Fi antenna packed under the foam that fastens onto the gold connector, a USB cable, and a small box of extras containing four power management cables and one extender cable.
Put the two devices side by side and the Pro is the chunkier of the pair, heavier and noticeably thicker, while the Plus is lighter and more compact. My mount has plenty of capacity so the weight was never a concern, but it's still a nice win.
The two changes I was really interested in are these. First, internal memory: the Plus comes with either 32GB or 256GB of internal eMMC storage (I went for the 256GB version), replacing the microSD card slot on the Pro, with read and write speeds around two and a half times faster. That really matters when you're saving large image files all night, or loading them back up to inspect mid-session. Second, that very obvious antenna hanging off the back, which significantly upgrades the Wi-Fi range and stability. Both devices can broadcast their own network or run in station mode, where the device joins your home Wi-Fi and you reach it through that. Station mode is what I'll use, since I like my phone and tablet to stay on my own network with internet access while I check in on the device.
There are two further differences worth mentioning. The Plus has a USB-C port that doesn't exist on the Pro, letting you connect directly to a computer by cable if you want to (I never will, but it's nice to have). And while the power ports are the same, four DC 12V outputs plus the input, the Plus adds proper power management in the app, with live usage stats so you can actually see whether you're overloading the device rather than running blind and hoping you made the right call.
So in summary: size, the extra USB-C port, the Wi-Fi improvements, the power management capabilities and the internal memory. Some pretty good upgrades in there.
Setting it up
With the unboxing done I hooked the Plus up to the telescope and worked through the app tab by tab, so it's ready to go the moment a clear night appears.
The device starts you off on its own network in 5G mode, which I switched over to station mode. On the power page you can watch the live readings update, and I assigned my four outputs: two dew heaters, the camera and the mount. For the main camera I connected the ASI 2600MM Pro with gain set to my usual 100 (this varies by camera, but it works well for me) and adjusted the cooling from the default of -20 to my usual target, something I plan to experiment with in time. I also enabled the anti-dew feature, which prevents water vapour and is one of the additions on the 2600MM that I think is worth having. File naming and the advanced settings I left at their defaults.
On the guiding side, I connected the ASI 120 Mini. I've found the default guiding aggression values very high with my mount, so I reduce them significantly, and I turn auto-restore calibration back on. Under the advanced guiding settings I gave the guide stability settle timer an actual sensible timeout of 60 seconds rather than the effectively unlimited default. Dithering is enabled with a distance of five pixels and an interval of three, so it dithers every third image, on both axes rather than RA only. The mount itself is configured as EQMod with Sky Safari, which is all that page needs.
The filter wheel deserves a special mention. The filters are just numbered by default, so I renamed them. I keep mine in a logical order, slots one to four as L, R, G and B, then five to seven as S, H and O. The names then show up when choosing the current filter and get included in the resulting file names, which makes life much clearer. I also enabled the one-way rotation mode, which is slower but higher precision; since the wheel isn't rotating constantly through the night, I think the extra precision is worth it.
Finally, the focuser and storage. The EAF defaults tend to be fine so I left them alone, and the eMMC tab shows about 233GB of the 256GB available after the system takes its share, which is a huge amount of room. In practice I'll write images to the eMMC overnight and transfer them to a USB stick afterwards; if you know a better way to get the data onto a computer without that extra step, I'm all ears.
First impressions of the speed
To finish, I ran some quick transfer tests with one-second exposures. Connected directly to the device's own 5G Wi-Fi, the transfer was pretty much instant, a marked difference from my experience with the Pro. Switching to station mode through my home network, I was seeing roughly 5 to 15MB per second, again much faster than the Pro managed. Loading a full FITS file of around 50MB back off the disk for editing was a bit slower but still pretty good. The caveat is that the device wasn't also running guiding and everything else involved in a night of imaging, so the load was low; I'll repeat the test out in the garden during a real session and report back.
Everything is now configured and waiting on the British weather, which is exactly as cooperative as you'd expect. If you'd like to see the Plus in the flesh, the full unboxing and setup is in the video above, and subscribing on YouTube is the easiest way to catch the follow-up once it gets its first proper night out. Clear skies!